Add a Timestamp.__float__ method

This allows float(Timestamp) to be used instead of Timestamp.to_float.
This helps to convert TimeRange.length into a float in one go by doing
float(TimeRange.length).

sem-ver: feature

Author: Philip de Nier

mediatimestamp/immutable/timestamp.py

@@ -429,7 +429,7 @@ def to_tai_sec_frac(self, fixed_size: bool = False) -> str:
     def to_float(self) -> float:
         """ Convert to a floating point number of seconds
         """
-        return self._value / Timestamp.MAX_NANOSEC
+        return self.__float__()
 
     def to_datetime(self) -> datetime:
         sec, nsec, sign, leap = self.to_unix()
@@ -665,6 +665,9 @@ def __floordiv__(self, anint: int) -> "Timestamp":
         ns = self._value // anint
         return Timestamp(ns=ns)
 
+    def __float__(self):
+        return self._value / Timestamp.MAX_NANOSEC
+
     def _get_fractional_seconds(self, fixed_size: bool = False) -> str:
         div = self.MAX_NANOSEC // 10
         rem = self.ns

tests/test_timerange.py

@@ -489,6 +489,11 @@ def test_length_negative(self):
 
         self._check_length(a, b, c)
 
+    def test_length_float(self):
+        self.assertEqual(TimeRange.eternity().length, float("inf"))
+        self.assertEqual(float(TimeRange.eternity().length), float("inf"))
+        self.assertEqual(float(TimeRange.from_str("[0:0_1:0)").length), 1.0)
+
     def test_repr(self):
         """This tests that the repr function turns time ranges into `eval`-able strings."""
         test_trs = [